Endovascular device for entrapment of participate matter and method for use

ABSTRACT

A method for filtering particulate matter from a blood vessel in a patient, including inserting a device into the blood vessel, the device including at least an outer structure capable of insertion into the blood vessel; and an inner filter anchored to the outer structure, the inner filter having a one-way valve though which a medical instrument may be passed.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/310,149, filed Dec. 5, 2002, entitled “Endovascular Device ForEntrapment Of Particulate And Method For Use”, which claims priorityfrom provisional application No. 60/335,838, filed on Dec. 5, 2001,entitled “Endovascular Device For Entrapment Of Emboli”.

FIELD OF THE INVENTION

The present invention relates to an endovascular device and method foruse, and in particular, to a device for trapping particulate such asemboli.

BACKGROUND OF THE INVENTION

Emboli form, for example, as a result of the presence of particulatematter in the bloodstream. Vascular emboli are a major single causativeagent for multiple human pathologies. It is a leading cause ofdisability and death. Clots or thrombi that become dislodged from thepoint of origin are termed emboli.

Such particulate matter may originate from a blood clot occurring in theheart. It may be a foreign body, but may also be derived from bodytissues. For example, atherosclerosis, or hardening of the blood vesselsfrom fatty and calcified deposits, may cause particulate emboli to form.Moreover, clots can form on the luminal surface of the atheroma, asplatelets, fibrin, red blood cells and activated clotting factors mayadhere to the surface of blood vessels to form a clot.

Blood clots or thrombi may also form in the veins of subjects who areimmobilized, particularly in the legs of bedridden or other immobilizedpatients. These clots may then travel in the bloodstream, potentially tothe arteries of the lungs, leading to a common, often-deadly diseasecalled ‘pulmonary embolus’. Thrombus formation, and subsequent movementto form an embolus, may occur in the heart or other parts of thearterial system, causing acute reduction of blood supply and henceischemia. The ischernic damage often leads to tissue necrosis of organssuch as the kidneys, retina, bowel, heart, limbs, brain or other organs,or even death.

Since emboli are typically particulate in nature, various types offilters have been proposed in an attempt to remove or divert suchparticles from the bloodstream before they can cause damage to bodilytissues.

For example, U.S. Pat. No. 6,258,120 discloses a filter device intendedto be inserted into the artery of a patient. However, the device has aninherent drawback, which is that the actual trapping of an embolus, forsuccessful operation of the device, may result in blockage of blood flowthrough the device and hence through the artery. Other disclosedembodiments of the device, which may not be blocked by clots, are notable to filter clots, and may in fact funnel such particulate matter tothe blood vessels leading to the brain. None of the disclosedembodiments of the device is anchored to the artery, but instead relyupon conformation to the arterial shape and size to maintain theposition of the device, which is not secure. In view of the naturalforce of blood pressure and elastic recoil of the arterial wall, properplacement and control of position of the device are of paramountimportance. If the device moves even slightly, it may even block theartery which it is intended to protect. Such movement may be caused byblood flow for example, as the blood pulse moves through the artery,

U.S. Pat. Nos. 4,873,978, 5,814,064, 5,800,457, 5,769,816, and 5,827,324describe devices that are intended only for temporary insertion into ablood vessel. Therefore, these devices avoid the difficult issue ofsimultaneously successfully filtering emboli while also maintainingblood flow through the blood vessel. As such, they do not address theproblem of prolonged filtration of the blood.

U.S. Pat. No. 5,234,458 appears to disclose a filter device that isintended to be left in the vessel for a period of time. However, thedisclosed filter device lacks a tapered shape, thus introduction andpositioning may be unsafe and complex. Such a device does not feature asufficiently strong anchoring system and the filter does not include amesh.

The lack of a suitable anchoring system is a general problem withdevices disclosed in the background art, as the pulsating blood flow,aortic elasticity and movement may all cause a device inserted into amajor blood vessel to become dislodged. Furthermore, those devices whichfeature rigid structures may create turbulent blood flow at certainlocations such as the aortic arch, leading to decreased cerebral bloodflow and possible activation of the clotting mechanism.

Therefore, there is a need for a more effective and safer device andmethod for protecting against particulate such as emboli.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide for a device and method forprotecting a blood vessel, and hence bodily tissues, against damagecaused by particulate such as an embolus. The device is typically astent, for insertion in a large artery such as the ascending aorta (asshown below), aortic arch or any artery in jeopardy, and is structuredas a filter and/or with filtering material. Other configurations can beused. The filtering structure is typically made of at least one layer ofmesh, which may be attached to the arterial wall. Typically only part ofthe device is attached (for example at a reinforcing structure or a ringstructure).

In one embodiment, the outer structure is a wire frame.

A device according to an embodiment of the present invention may featurea plurality of layers. The outer layer is typically made of a dilatableand/or otherwise self-expanding tubular structure. This tubularstructure is typically anchored to the vascular wall after dilation tothe size and shape of the vessel, or to the diameter of the bloodvessel. Anchoring components, such as fine pins, maybe employed foranchoring the device to the tissues of the vascular wall. The materialof which the device is constructed may optionally be metallic. Othermaterials may be used.

According to one embodiment, the device includes a first typically outercage-like structure (such as a stent) for holding an inner net. The netis able to filter the particulate matter. More typically, at least thenet is manufactured from a flexible thread such as surgical monofilamentsutures suitable for insertion into the body and/or for medical use.Other materials may be used. For example, metallic material, such astitanium, gold, and/or suitable alloys may be used.

The stent is typically constructed so that material of the typicallyinner and typically more pliable net cannot inadvertently becomeinserted into the openings of the important branching vessels, if thedevice is inserted into the aortic arch, for example. The device mayfeature a plurality of layers, including at least an inner layer and anouter layer. The inner layer is typically constructed of a pliable net,with relatively small openings, so that blood can flow through the netfreely, but not emboli. The size of the mesh is typically such that itpermits passage of blood and micro-emboli, for example according to theorgan system, which is to be protected. The distal part of the net istypically narrowed, and more typically features two layers of the samematerial. The free edges may be reinforced with, for example, a weave ofmetallic thread, such as gold. The layers therefore typically form abasket like structure with overlapping layers at one end, which are notsealed, but instead may optionally be opened upon retrograde motionthrough the distal end of the net structure. Therefore, emboli can betrapped in the net structure, as they typically float in the blood flow,but diagnostic and/or therapeutic catheters may optionally enter theaortic arch (or any other blood vessel in which the device of thepresent invention is installed) through the distal end of the net. Inother words, in such an embodiment, the distal part of the net forms atrap for emboli, with a one-way valve, allowing passage of medicalinstruments.

A temporary component may be added to the device, for example for useduring heart and aortic surgery, with extracorporeal circulation afterthe device has been inserted to the blood vessel. Such a temporarycomponent may be implemented as, for example, an inner mesh, which isoptionally inserted into the device in order to trap micro-emboli duringsurgery. This mesh with the entrapped contents is then typically removedat the end of the surgical procedure.

The device according to one embodiment of the present invention may beinsertable into a blood vessel in a wrapped or compressed form by, forexample, using a catheter, according to, for example, the SeldingerTechnique. The deployment site may be optionally determined by anynumber of imaging methods, including but not limited to X-rayfluoroscopy, intravascular ultrasound, or echocardiography, MRI(magnetic resonance imaging), angioscopy, CT (computerized tomography)scan, and/or any other suitable imaging technology. Another optionalmode of deployment is surgical, by direct insertion of the cathetercarrying the device through a puncture of the targeted vessel inproximity to the deployment site.

The device of the present invention may optionally serve as a platformfor carrying physiologic, hematological, biochemical and so forthmicro-sensors. Enabling continued monitoring of one or more parameters,such as temperature, blood pressure, heart rhythm, blood flow (‘cardiacoutput’), pH, electrolytes, blood sugar, blood LDL etc. Thesemicroprocessors typically transmit the data (for example) wirelessly toan outer monitoring device, as needed. The device can be loaded bycoating or small aggregates, to serve as an internal “docking station”to release drugs, hormones, genes and so forth either automatically orby sensor-reactor programming, servomechanism or external control.

The device and method are particularly useful in preventing blockages offlow to the brain, but have other uses as well.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a device according to an embodiment ofthe present invention, shown inserted into the ascending aorta;

FIG. 2 a shows the outer mesh layer of the device of FIG. 1 according toan embodiment of the present invention;

FIG. 2 b depicts details of the device-of FIG. 1 according to anembodiment of the present invention;

FIG. 3 a shows the inner mesh layer of the device of FIG. 1 according toan embodiment of the present invention;

FIG. 3 b details of the device of FIG. 1 according to an embodiment ofthe present invention;

FIG. 4 depicts an embodiment where an inner filter or net provides focalcoverage for an area to be protected; and

FIG. 5 is a flowchart depicting a series of steps according to oneembodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

In the following description, various aspects of the present inventionwill be described. For purposes of explanation, specific configurationsand details are set forth in order to provide a thorough understandingof the present invention. However, it will also be apparent to oneskilled in the art that the present invention may be practiced withoutthe specific details presented herein. Furthermore, well-known featuresmay be omitted or simplified in order not to obscure the presentinvention.

Embodiments of the present invention provide for a device for protectingbody organs such as the brain and hence bodily tissues, against damagecaused by particulate matter such as an embolus. The device is typicallyin a stent configuration, for insertion in a large artery such as theaorta (as shown below), structured as a filter and/or with filteringmaterial. Other configurations are possible. The filtering structure istypically made of at least one layer of mesh, which is attached to thearterial wall. Other numbers of mesh layers may be used. Typically onlypart of the device is attached (for example at a reinforcing structureor a ring structure).

Devices according to embodiments of the present invention typicallyincludes a plurality of layers. The outer layer is typically made of atypically dilatable and/or otherwise self-expanding tubular structure orstent.-The stent is typically not required to dilate the artery andserves as an outer skeleton, stabilizer and protector of the innerstructure. Other outer structures may be used. This tubular structure istypically anchored to the vascular wall after dilation to the size andshape of the vessel, or at least to the diameter of the blood vessel andpossibly, to ensure good contact and stabilization. More typically,anchoring components, such as fine pins, are employed for anchoring thedevice to the tissues of the vascular wall, although such anchoringcomponents need not be used. The material of which the device isconstructed may optionally be metallic, but other suitable materials maybe used.

Typically, the device includes a first cage-like structure for holding anet, in which the net is able to filter the particulate matter. The net(and possible other components) is constructed of a flexible, finethread which is suitable for insertion into the body and/or for medicaluse. Other materials may be used, such as titanium, gold, and/orsuitable alloys.

The outer stent is typically constructed such that material of the netcannot inadvertently become inserted into the openings of the importantbranching vessels, if the device is inserted into the aortic arch, forexample. More typically, the net features a plurality of layers,including at least an inner layer and an outer layer. The inner layer istypically constructed of a pliable net, with relatively small openings,so that blood can flow through the net freely, but not certainparticulate matter such as emboli. The size of the mesh is typically ina range which permits emboli that may pose a danger to organs in thebody to be trapped, and is more typically selected according to thelocation of the device within the body.

The distal part of the net is optionally and typically narrowed, andmore typically features two layers of the same material. The free edgesare typically reinforced with a reinforcing structure, such as weavinggold thread or thread or material of, typically, any relatively heavier.More typically, such reinforcement causes that portion to be somewhatthicker and heavier, such that the ends of the net remain distal to thecage-like outer structure and also remain open at the distal part. Thelayers therefore typically form a basket-like structure with overlappinglayers at one end, which are not sealed, but instead may optionally beopened upon retrograde motion through the distal end of the netstructure. Therefore, emboli or other particulate can be trapped in thenet structure, but diagnostic and/or therapeutic catheters mayoptionally enter the aortic arch (or any other blood vessel in which thedevice of the present invention is installed) through the distal end ofthe net. In other words the distal part of the net forms a trap foremboli or other particulate, with a one-way valve, allowing passage ofmedical instruments.

This distal structure may be suitable for passage of, for example,therapeutic endovascular catheters for removal of entrapped debris andclots by way of mechanical clot extraction, ultrasonic cavitation,LASER, local delivery of thrombolytic agents such, as t-PA for example,and other suitable therapies. The distal structure can also optionallybe used for insertion of cardiovascular angio graphic catheters as wellas therapeutic balloon catheters, drills, stents and so forth.

In one embodiment, a temporary component may be added to the device, forexample for use during heart and aortic surgery, after the device hasbeen inserted to the blood vessel. Such a temporary component istypically implemented as an inner mesh, which is optionally insertedinto the device in order to trap, for example, micro emboli duringsurgery. This mesh with the entrapped contents is then typicallyre-wrapped, and removed at the end of the surgical procedure.

A device according to an embodiment of the present invention istypically insertable into a blood vessel in a folded or compressed formby using a catheter, according to the ‘Seldinger Technique’. Thedeployment site is optionally determined by any number of visualizationmethods, including but not limited to X-ray fluoroscopy, ultrasound (orechocardiography), MRI (magnetic resonance imaging), direct angioscopy,near infrared angiology, intra-vascular ultrasound, CT (computerizedtomography) scan, and/or any other suitable imaging technology. Anotheroptional mode of deployment is surgical, by direct insertion of thecatheter carrying the device through a puncture of the targeted vesselin proximity to the deployment site.

A device according to an embodiment of the present invention mayoptionally serve as a platform for carrying, for example, physiologicmicro-sensors, such as temperature, blood pressure, heart rhythm, bloodflow (e.g., ‘cardiac output’), pH, electrolytes, blood sugar, blood LDLetc. These microprocessors typically transmit the data, typicallywirelessly, to an outer monitoring device, as needed.

In one embodiment, due to the relatively large diameter of the device asa whole, a very large embolus is typically required to impede blood flowacross the entire device. Smaller emboli, which would be caught in thefilter of the device, might dissolve spontaneously or, for example,could be treated with drugs. Typically, minute micro-emboli are allowedto pass through the device, as they should not cause major damage toorgans. The size of the mesh can be adjusted as suitable.

Embodiments of the present invention may have various medicalapplications, including but not limited to, prevention or treatment ofblockage of any blood vessel or any other bodily passage, such as thecarotid artery, aorta, veins and so forth; prevention or treatment ofblockage of any blood vessel or any other bodily passage which issecondary to medical treatment, such as catheterization; and use of thedevice to overcome medical conditions which may cause or exacerbate theformation of blood clots in the patient. Embodiments may also optionallybe used as an adjunct during surgery, for example with the addition of atemporary filter in the device with mesh having relatively small holes;this temporary filter maybe removed after surgery.

FIG. 1 is a schematic diagram of a device according to an embodiment ofthe present invention, shown inserted into the ascending aorta. Asshown, a device 7 is inserted into ascending aorta 1 for the purposes ofillustration only and without any intention of being limiting. Othermethods of insertion and positions of insertion and use may be used.Device 7 also may be suitable for, for example, insertion into a numberof major blood vessels in the body. As shown in FIG. 1, when insertedinto ascending aorta 1, device 7 is typically placed beneath, andphysically adjacent to, brachiocephalic artery 3, left carotid artery 4and left subdlavian artery 5. Device 7 may optionally attenuate movementof ascending aorta 1 slightly with each blood pulse, but withoutsignificantly impeding the action of aorta 1.

In one embodiment, device 7, or at least a portion thereof, also extendsinto the descending thoracic aorta 6. This placement provides highprotection for different organs in the body. Briefly, this placementprevents particulate matter (of at least a size to be trapped by device7) from entering the brain. In addition, by preventing entry ofparticulate matter to the brain, transmission of such particulate matterto more distal organs, such as the kidneys and liver for example, isalso prevented. Also, this location enables trapped material to be moreeasily and more safely removed.

In the embodiment shown, device 7 typically features an outer orexternal structure 2, which is more typically in the structure,construction, configuration or shape of a stent. Such a shape istypically tubular or cylindrical, and fits closely to the-surface of theblood vessel into which device 7 has been inserted, which is ascendingaorta 1 in this example. External structure 2 is typically capable ofinsertion into a blood vessel. Outer or external structure 2 istypically a cage-like structure, featuring typically a stent which actsas both an external support skeleton and also as secondary physicalprotection. Furthermore the stent may prevent the net from entering abranch and potentially occluding the blood flow. The stent typicallyfeatures relatively large apertures, as shown with regard to FIG. 2.Typically, the stent or outer structure includes holes or openings of afirst size, and the inner mesh or filter or structure includes holes oropenings of a second size, the first size being typically larger thanthe second size. Typically the size of the apertures of the net may besmaller in the part facing the arterial branch to be protected. The sizeof the holes in the net are typically small enough to filter almost allemboli causing significant disease, but allowing free flow of blood. Thepressure gradient across the device in the blood stream typically causesonly minor pressure-drop (less than 10%); other pressure drops arepossible. Other configurations and shapes, and other mesh sizes, may beused. For example, the external structure may be wire frame, such as theone depicted in FIG. 4 below. Such a structure may include a number ofbends.

In one embodiment, outer or external structure 2 includes “void” areasor spaces facing certain vessel openings, such as on the ‘top’ sidefacing the aortic arch vessels, namely the right innominate artery (alsocalled the brachiocephalic artery), the left carotid artery, and theleft subelavian artery). Other positions for such voids may be used, andvoids need not be used.

In one embodiment, outer or external structure 2 is a ‘bent’ tubularstent with, typically, a few parallel bars which are interposed by,typically, a few lateral thin wires to maintain physical form andstrength. In one embodiment, the total length of outer or externalstructure 2 complies with the distance in the body, and its width viendilated is 20-30 mm according to the individual aortic width. Otherdimensions may be used.

In one embodiment, the geometry of the external structure 2 enables easyfolding. The external structure 2 typically includes an outer diameterof less than 9 French or 3 mm, but other dimensions may be used.

Device 7 also typically includes an internal structure such as a filteror net 16 for trapping particulate such as emboli, which is typicallylocated within, and anchored to, external structure 2. Other trapping orfiltering structures may be used. Internal filter or net 16 typicallyfeatures a relatively fine net which functions as a filter, and moretypically extends beyond external structure 2. Such extension need notbe used. Internal filter or net 16 is typically flexible.

Typically, the internal structure is kept a certain, lateral distancefrom the walls of the surrounding artery. This may help in preventingflow into branch vessels from being impeded.

When used in the position shown, such an extension of the material ofinternal net 16 may prevent any trapped particulate matter from blockingblood flow to those previously described major blood vessels, as well assupporting the continued flow of blood through the entirety of device 7.Internal net 16 also most typically features a tapered shape,particularly for the portion which extends beyond external structure 2,again for the purpose of preventing particulate matter from blocking theflow of blood through device 7 and/or the blood vessel itself. Inalternate embodiments, other internal structures may be used, such asother filters or nets. The internal structure may have a different shapeor configuration.

In one embodiment, an electric charge may be placed on the device, sothat, for example, blood components such as proteins do not collect onor adhere to the external structure 2. For example, an electric chargecan be achieved by the addition of metals and/or polymers that arenaturally charged, or, alternately, by incorporating piezo-electricmaterials or piezo-electric cells which may generate charges (forexample, up to 100-200 milivolts). Such piezo-electric materials orpiezo-electric cells may generate electricity or electric charges byeven minor physical changes in position, caused by, for example, thechanges in blood pressure during the cardiac cycle (systolic/diastolicpressure).

FIG. 2 shows one embodiment of the outer mesh layer of the device ofFIG. 1, showing the components separately from the remainder of thedevice. External structure 2 typically features a mesh 12 havingrelatively large apertures or holes, for trapping relatively largeemboli and/or other particulate matter. Other sizes and shapes may beused.

External structure 2 is optionally and typically anchored to the wall ofthe aorta 1. Such anchoring structure may include, for example, at leastone pin 13. Other mounting methods and devices may be used.

Typically, external structure 2 includes at least one, and moretypically a plurality of, support interconnection components, shown as aproximal support interconnection component 9 and a distal supportinterconnection component 11. Interconnection components 9 and 11 maybe, for example, rings, or sutures but may be other types of structures.Other types and numbers of support interconnection 5 components may beused. A plurality of pins 13 (shown in detail FIG. 2A) are moretypically used to anchor external structure 2 to the wall of ascendingaorta 1. Pin(s) 13 typically attach each of proximal supportinterconnection component 9 and distal support interconnection component11 to the wall of ascending aorta 1.

External structure 2 also typically features one or a plurality ofconnections between the outer stent and the inner net for connectingmesh 12 to the internal net (FIG. 3), to prevent the latter from beingdislodged from the blood vessel, and/or from being moved within theblood vessel. Such movement might inadvertently block blood flow to oneof the other arteries shown in FIG. 1, for example. Other suitableconnection methods may be used.

In one embodiment, external structure 2 features a plurality of devicessuch as micro sensors 14 and 15 for sensing physiological functions orparameters, such as, for example, blood pressure, ECG, heart rate, pHvalues, temperature, velocity, oxygen saturation and content, as well asfor any biochemical, endocrine, or hematological status including, forexample, clotting mechanism and factors, or any drug concentration (seealso FIG. 2A). Micro-sensors 14 and 15 may be, for example, attached toa support platform 10. Support platform 10 may be thicker and stiffer,to conform to the natural shape of the aortic arch. Other methods ofattaching additional devices may be used, having other configurations.Micro sensors could be coupled, for example, with adjusted releasemechanisms for, for example, glucose, insulin, or other substances.

FIG. 3 shows one embodiment of the inner mesh layer of the device ofFIG. 1, featuring the internal filter or net 16. Optionally and moretypically, the distal end of internal net 16 is constructed as a one-wayvalve 18, made of, for example, two layers, flaps or leaflets of the netmaterial. The overlap enables retrograde insertion of catheters. The twolayers or leaflets of the net or filter material typically featureweights 17, for prevention of movement of the distal end of internal net16 backward (see also detail FIG. 3A). One leaf or layer may be extendfurther than the other, curving around the tip of the net 16. Otherconfigurations for the inner mesh layer may be used. For example, suchone-way valve need not be used, and weights need not be used.Furthermore, if a valve is included, the valve may include otherconfigurations.

In one embodiment, internal net 16 is made of two or more leaves or flatportions, typically connected along the sides, tapered towards theiroutlet ends, with one slightly longer than the other, and not connectedat the distal end. One leaf may be longer than the other, curving aroundthe tip. The two leaves may be interconnected at multiple sites(points), but spaced at the distal end, to form, for example, a valveallowing easy passage from the distal end but not from the lumen. An‘active valve’ may thus be formed. Particles can not pass distally but acatheter can be passed from the distal end proximally. Other shapes forthe leaves may be used, and a leaf structure need not be used.

This distal structure may be suitable for passage of, for example,therapeutic endovascular catheters for, for example, removal ofentrapped debris and clots by way of mechanical clot extraction,ultra-sonic cavitation, LASER, local delivery of thrombolytic agentssuch as t-PA for example, and other suitable therapies. The distalstructure can also optionally be used for insertion of cardiovascularangiographic catheters as well as therapeutic balloon catheters forValvuloplasty, drills, stents Electrophysiology catheters, clot removaldevice and so forth.

In a further embodiment, an inner filter or structure may be shaped andsized to protect only a portion of the area within the outer structure.Such a “focal” filter may enable free passage through a portion of theouter structure of devices such as catheters, for example to aid inprocedures of angioplasty, percutanous valvuloplasty, or otherprocedures. FIG. 4 depicts an embodiment where an inner filter or netprovides focal coverage for an area to be protected. Referring to FIG.4, outer structure 5.0 includes an inner net or filter 52, which coversonly a portion of the area of the outer structure. For example, innerfilter 52 may protect or filter blood flow to the brain when properlyinserted. Outer structure 50 is a wire frame as opposed to a stent likestructure, but may also be a stent like structure.

Typically, inner filter 52 faces one branch for which protection isdesired, such as (given one possible configuration and placement) one ofthe right innominate artery, the left carotid artery, and/or the leftsubclavian artery. More than one such filter may be included, coveringmore than one branch, or one filter may cover more than one branch. Suchan embodiment may, for example, protect the brain (vessels leading tothe brain) but not other branches or areas, such as the distal branches(e.g., the renal arteries, femoral arteries, etc). In alternateembodiments, configurations may differ, and if placement differs,different areas may be protected. Outer structure 50 may alternatelyinclude a filter as described in FIGS. 1-3.

The wire 51 forming outer structure 50 typically contacts thesurrounding blood vessel at every or almost every point along the wire51, but need not. In the embodiment shown, the outer structure 50 is a“tripod” structure with three main sections or lobes, but may have fouror other numbers of sections. Such an outer structure 50 may beparticularly suited for easy folding and positioning, by, for example,being wrapped or folded to a relatively small size of, for example, 9-10F, such that it is passable through the femoral artery. Other insertionmethods may be used.

In one embodiment, a device according to an embodiment of the presentinvention can be inserted as, for example, protection from brain emboliprior to an invasive intracardiac procedure, such as balloon aorticvalvuloplasty, balloon mitral valvuloplsty, electrophysiologicalstudies, with or without ablation of ectopic rhythmic sites, insertionof automatic defibrilators, percutaneous valve repair or replacement, orother procedures. Embodiments of the device can be used, for example, inpatients with severe aortic atheroma for brain protection during routineheart catheterization, or for endovascular “cleaning” of atheromatous orthrombotic material. Such an embodiment could be used in patients withhigh risk or propensity to form intracardiac clots, for example patientswith hematological disease, arrhythmia of the heart, artificial heartpatients, assist-device patients, mechanical valve replacement patients,patients following intracardiac repair of a pathology, or patients withcongenital heart disease such as patent foramen ovale, and so forth.

FIG. 5 is a flowchart depicting a series of steps according to oneembodiment of the present invention. Referring to FIG. 5, in step 100, adevice, such as an embodiment of the device described above, is insertedinto a patient's blood vessel. In one embodiment, the insertion may beperformed during an insertion procedure, and the device may remain inthe blood vessel after the insertion procedure is complete.

In one embodiment, the device is inserted in a “wrapped” form. The outerdiameter of the wrapped device enables introduction via a peripheralartery, such as the common femoral artery, using the OTW technique orSeldinger technique. An alternate mode of insertion may be, for example,surgical. The surgeon can insert the device OTW through a direct needlepuncture of the artery. Other insertion methods may be used.

In step 110, optionally, an additional filter may be inserted into orotherwise connected to the device, for example during the duration of asurgical procedure. The additional filter is typically removed after thesurgical procedure is complete.

In step 120, optionally, the patient may be treated with a drug, forexample, a drug for endocarditis or blood clots.

Other steps or series of steps may be-performed. For example, the methodmay additionally include dilating a valve of the patient with acatheter. In addition, the inner filter may be removed or replacedwithout removing the outer structure.

A device according to an embodiment of the present invention can beused, for example, temporarily for acute conditions. For example, thedevice can be inserted for the duration, or the known duration, of thecondition. For example, the device may be inserted temporarily toprotect against cardio embolic stroke or embolic stroke. Currently,patients with acute myocardial infarction (AMI) show an incidence of 35%of clots in the heart (Left Ventricle), and 2% will have major stroke ordeath from this cardio embolic stroke or embolic stroke.

In alternate embodiments, the device can be coated by a structure orsubstance for better tissue adaption and biocompatibility. The devicecan include pharmacologic or genetic agents, thus serving as a platformfor controlled release of any substance, where it is needed.

Other conditions may warrant insertion. In other embodiments, the devicemaybe inserted for a long-term period, or permanently. In furtherembodiments, the device maybe inserted for the duration of a procedureor treatment.

In further embodiments, portions of the device, such as the innerfilter, may be wholly or partially biodegradeable.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather the scope of the present invention isdefined only by the claims which follow:

1. A method for filtering particulate matter from a blood vessel in apatient, the method comprising: inserting a device into the bloodvessel, said device including at least: an outer structure capable ofinsertion into the blood vessel; and an inner filter anchored to saidouter structure, said inner filter having a one-way valve though which amedical instrument may be passed.
 2. The method of claim 1 comprising:inserting said device into the blood vessel during an insertionprocedure; and allowing said device to remain in the blood vessel aftersaid insertion procedure is complete.
 3. The method of claim 1comprising: inserting an additional filter into said device during asurgical procedure; and removing said additional filter after saidsurgical procedure is complete.
 4. The method of claim 1 comprisingtreating the patient with a drug for endocarditis.
 5. The method ofclaim 1, the method comprising treating the patient with a drug forblood clots.
 6. The method of claim l, the method comprising dilating avalve of the patient with a catheter.
 7. The method of claim 1,comprising inserting the device to protect against cardio embolicstroke.
 8. A method for filtering particulate matter from a bloodvessel, the method comprising: providing a device for being insertedinto the blood vessel, said device featuring: an outer structure forconforming to a shape of the blood vessel; and an inner filter anchoredto said outer structure, said inner filter for filtering the particulatematter, said inner filter having a portion extending beyond said outerstructure, said extended portion being at least partially flexible, saidinner filter having a one-way valve through which a medical instrumentmay be passed; and inserting said device into the blood vessel during aninsertion procedure; and allowing said device to remain in the bloodvessel after said insertion procedure is complete for filtering theparticulate matter.
 9. The method of claim 8, further comprising:inserting an additional filter into said device during a surgicalprocedure; and removing said additional filter after said surgicalprocedure is complete.